Cobicistat is a potent inhibitor of cytochrome P450 3A enzymes, including the important CYP3A4 subtype. It also inhibits intestinal transport proteins, and thereby may increase the overall absorption of several HIV medications, including atazanavir, darunavir, and tenofovir alafenamide fumarate.
Cobicistat is chemically known as 1,3-thiazol-5-ylmethyl [(2R,5R)-5-{[(2S)2-[(methyl {[2-(propan-2-yl)-1,3-thiazol-4-yl]methyl}carbamoyl)amino]-4-(morpholin-4yl)butanoyl]amino}-1,6-diphenylhexan-2-yl]carbamate, illustrated in Formula 1 below.

U.S. Pat. No. 8,148,374 patent (which is hereby incorporated by reference) discloses cobicistat and pharmaceutically acceptable salts thereof.
The present disclosure provides a novel crystalline compound of formula 8 and an improved process for the preparation of cobicistat using compound of formula 8.